function normalizeAmount(value) {
  if (value == null) {
    return null;
  }

  const numberValue = Number(value);
  if (!Number.isFinite(numberValue)) {
    return null;
  }

  return numberValue.toFixed(2);
}

async function runMockVerification({ invoice }) {
  const remarks = String(invoice.remarks ?? "").toLowerCase();
  const invoiceCode = String(invoice.invoice_code ?? "").toUpperCase();
  const invoiceNumber = String(invoice.invoice_number ?? "").toUpperCase();

  if (remarks.includes("verify-error") || invoiceNumber.includes("ERR")) {
    return {
      status: "error",
      resultCode: "mock_transport_error",
      resultMessage: "mock provider transport error",
      payload: {
        provider: "mock",
        marker: "verify-error",
      },
    };
  }

  if (remarks.includes("verify-fail") || invoiceCode.includes("FAIL") || invoiceNumber.includes("FAIL")) {
    return {
      status: "failed",
      resultCode: "invoice_mismatch",
      resultMessage: "invoice metadata mismatch",
      payload: {
        provider: "mock",
        matched: false,
      },
    };
  }

  return {
    status: "passed",
    resultCode: "verified",
    resultMessage: "invoice verified",
    payload: {
      provider: "mock",
      matched: true,
      invoiceCode: invoice.invoice_code ?? null,
      invoiceNumber: invoice.invoice_number ?? null,
      totalAmount: normalizeAmount(invoice.total_amount),
    },
  };
}

module.exports = {
  runMockVerification,
};